Apparatus for automatically ventilating buildings such as winter gardens, sun lounges, and greenhouses

ABSTRACT

The invention relates to an apparatus for venting a building such as a greenhouse, by means of a sheet member which can be mounted in one or several openings of the building. The sheet member comprises a frame with four sides wherein are provided on at least two horizontal controls, which are formed as first rack bars. The frame has a horizontal edging and several parallel slats provided on at least one side hereof with a layer made of windproof and elastic material. A pinion is mounted in rotatable position opposite each guide on the edging, said pinion comprising a first and a second gear, the first gear being in mesh with the mentioned first rack bars, and the second being in mesh with teeth on the second rack mounted in movable position on the edging. A movement by the second rack bar in longitudinal direction will cause the second gear and consequently the first gear as well to rotate, whereby the edging is caused to move upwards or downwards via the first rack bars depending upon the direction of movement of the second rack bar. Consequently, the layer will either close off or clear an opening to the effect that air may vent the interior of the building.

FIELD OF THE INVENTION

The present invention relates to a method of venting buildings providedwith walls and roofs of transparent material, such as winter gardens,sun lounges or greenhouses, wherein an air current is created by adifference of temperature between at least two openings provided atdifferent heights, and wherein the said openings can be opened or closedby means of sheet members, such as windows or hatches, which areactivated by activation means.

BACKGROUND OF THE INVENTION

Certain types of buildings are provided with walls and roofs oftransparent material in the form of glass or plastics in order toutilize the solar energy for heating the interior of the building intemperate climates. Such buildings are winter gardens, sun lounges orgreenhouses.

Even in regions having a temperate climate, however, the solar energymay be so intense that the inside temperature of the building becomesundesirably high, and the building is then ventilated by opening atleast one window, and in case a more intensive ventilation is called forby attempting to make a draught by opening windows located at twoopposite sides of the building in order to take advantage of thedifference in wind pressures. Another possibility is to utilize thedifferences of temperature inside the building by opening windowslocated at different heights, thereby taking advantage of the so-calledchimney effect for ventilation of the building. In that case the windowsmay be provided either on a roof surface or in a wall, or in one wall,or in a first wall extending down from a roof surface, and a second wallextending down from the roof surface like a kind of chimney, which isparticularly common in winter gardens built adjacent to a residentialproperty.

It is well-known that the chimney effect is produced by the differenceof density between cold and warm air, causing the warm air to rise andleave the building through the upper opening, whereas the rising warmair is replaced by colder air entering through the lower opening.

The above described effect is known for example from DE PrintedSpecification no. 1,008,517 and GB Patent Specification no. 1,352,622.

DE Printed Specification no. 1.008,517 describes a greenhouse, which isprovided with openings at the bottom along the edge of one wall, whichopenings may be covered by flaps. In addition, the greenhouse has aridge turret with openings, whereby the wind can blow horizontallythrough the ridge turret thereby producing an ejector effect, which maystrengthen the chimney effect between the opening at the bottom alongthe edge of the greenhouse and the ridge turret.

GB Patent Specification 1,352,622 describes a greenhouse, which isprovided with openings at the bottom along the edge of two oppositewalls. These openings are fitted with sheet members, which are adaptedto slide in vertical direction to open respectively close the openings,said openings being further provided with nozzles to spray water on theentering air in order to cool down the air by evaporation of the waterand to increase the amount of steam and thus improve growth conditionsfor the plants in the greenhouse. Heated air can escape through openingsin the roof. The flaps are slidable or can be controlled by means of arack-and-pinion drive or with the aid of pneumatic cylinders, which maybe activated by thermostats.

For rational operation greenhouses are usually very long, for example upto 100 meters. Using a rack-and-pinion drive to open and close theopenings will result in considerable drawbacks, see for example DKPrinted Specification no. 148,761, in view of the fact that the changingtemperatures in the greenhouses on a day and night basis will cause thevarious shafts etc. to vary in length, requiring the provision ofspecial measures in order to correct the engagement of the rack barswith other parts of the mechanism, thereby rendering theserack-and-pinion drives unduly expensive to use.

It is known to use activation means based upon a cylinder to open thewindows of hotbeds or greenhouses, whereby the cylinder contains afluid, which will expand or contract when heated respectively cooled, asa result of which a piston in the cylinder will move accordingly andthereby open or close the window openings, see for example DE PrintedSpecification no. 1,043,703.

The above mentioned specifications provide solutions, which arecomplicated and therefore unduly expensive to use, irrespective ofwhether they are to be used in very long greenhouses for cultivation ofplants for commercial purposes, or whether they are to be used in a sunlounge or a winter garden comprising a few square meters only of aprivate residence.

SUMMARY OF THE INVENTION

It is an object of this invention to provide a method of ventingbuildings of the above described kind, wherein the chimmney effect is ashigh as possible, produced by very simple means, and can be adjustedautomatically without human interference, and wherein the means areeconomical in use over a long period of time without maintenance.

This object is achieved by a method of the kind described in theintroduction, and the novel features which characterize this inventionare that at least the lower opening is provided with a sheet memberhaving a layer of windproof and elastic material secured to at least oneside of several horizontal lamellas or slats mounted at equal distance,said lamellas or slats being slidable in vertical direction by means ofan activation device with a temperature detecting unit provided on theside of the slats facing the interior of the building.

By providing the lower opening with a curtain consisting of at least onelayer of windproof and elastic material secured to the edge ofhorizontal lamellas or slats mounted at equal distance, a sheet memberis produced, the height of which is simple to adjust in accordance withthe desired ventilation, and the adjustment of which is independent ofthe wind pressures prevailing around the building, in addition to whichthe sheet member is inexpensive to produce as well as to maintain. Bymeans of a temperature detecting unit provided on the inside of thecurtain it is achieved that the unit will react to the insidetemperature of the building only, and is protected against directinfluence from the cold outside air.

A sheet member, which can be produced as a unit in standard sizes, ishereby provided, and the unit can be installed in a simple way, and atthe same time it contains all of the means necessary for firm control ofthe horizontal slats. Largely, the length of the frame is arbitrary, anddepending upon the length the frame may be provided with more than twocontrols for guidance of the slats.

A similar mechanism is known from U.S. Pat. No. 1,209,085, whichprovides a jack for raising an automobile. The known jack comprises arectangular frame, which in each corner has a vertical rack bar, whichis slidably guided in a bushing. The pair of rack bars in each side ofthe frame are in mesh with a first gear, which is mounted locked againstmovement on a shaft, which is embedded in rotatable position on theframe and has a second gear at one end, secured and locked againstmovement to the shaft as well. These two second gears are in mesh with arack bar extending along one end of the frame and are slidably mountedin its longitudinal direction. The center of the rack bar is formed witha piston, which travels in a cylinder, and venting means have beenprovided to lead air from one end of the piston or the other to theeffect that the rack bar will move, thereby causing the mentioned secondset of gears to rotate, whereby the engagement of the first set of gearswith the vertical rack bars will cause these to move up or down.

By using this known mechanism in connection with the present invention,a particularly advantageous parallel control of the slats is achieved,irrespective of their length and the number of controls provided in theframe, and the dimension of the mechanism in a direction at right anglesto the plane of the frame can be kept very small.

A simple and very economical temperature detecting device is providedwhen using a hydraulic cylinder with a piston and a piston rod where thecylinder is connected to the slat carrying the shaft, and the piston rodis connected to the second rack bar.

When the cylinder unit is heated or cooled its length will change,causing the second rack bar to move. It is particularly advantageous toform the piston with a section smaller than that of the cylinder, sinceit is possible to achieve suitable variations of lengths as far as thecylinder unit is concerned by appropriate adaptation of the twosections.

The hydraulic cylinder, which is described in the above mentioned DEPrinted Specification No. 1,043,703, is used to open or close a glasswindow, and the cylinder will act upon the window frame located on theedge, which is offset from the hinge, whereby the cylindrical unit ofthe said window is subjected to the influence of the prevailing winddirections in an uncontrolled way, which may cause either that thewindow will open more than intended in consideration of the prevailingtemperature, or vice versa it may cause the window to open less thandesired.

In the method according to the invention the full benefit is derivedfrom a hydraulic cylinder which is unaffected by prevailing pressuresand directions of the wind.

Finally, it is advantageous to shield off the hydraulic cylinder so asto protect it against the effect of the incoming cold air as much aspossible, reacting only to the temperature prevailing in the buildingonly.

The invention also relates to a sheet member for use in theimplementation of the method according to the invention.

The advantages of the sheet member as well as the construction of thismember will appear from the detailed description below.

The method as well as the sheet member are described in detail withreference to the drawing, which illustrate an embodiment of a sheetmember, and in which:

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a side view of a sheet member according to the invention,

FIG. 2 is a plan view of a slat, which is part of a curtain of the sheetmember illustrated in FIG. 1,

FIG. 3 is a longitudinal section of one end of an edging forming theedge of a curtain of the sheet member, and

FIG. 4a and 4b are cross sections along the line IV--IV of the sheetmember in closed and opened position respectively.

DETAILED DESCRIPTION OF THE INVENTION

FIG. 1 illustrates a sheet member according to the invention, comprisinga right-angled frame 1, which is preferably rectangular and consists oftwo long sides 2, 3 and two short sides 4, 5. The sides 2-5 can be madefrom any suitable material such as plastic, wood or metal. If a metal isused, aluminium is preferred, or an aluminium alloy, which is suitablefor extrusion to the effect that the cross section of the sides 2-5 canbe formed in an appropriate manner, in addition to which corrosionresistance can a be obtained as well when using aluminium. Each of thesides 2-5 may also be composed of profiles, as indicated in FIGS. 4a and4b .

The four sides of the frame 1 may be assembled by means of weldings 6 orby appropriate connecting devices, such as screws and nuts or spikes.The ends of the sides 2-5 may be provided with cooperating grooves andtongues for mutual control of the ends, while the frame 1 may then beheld together merely by inserting it into an opening, the dimensions ofwhich correspond the outside measures of the frame 1.

The frame 1 is adapted to be installed in the wall of a building havingwalls and/or roof of transparent material to the effect that thebuilding can be heated by solar energy, and preferably the frame 1should be of a length corresponding to the entire length of the wall,and the sheet member in the lower opening is usually placed with one ofits long sides 3 parallel to the ground, preferably disposed against theground or the foundation of the building.

On the surfaces of the two short sides 4, 5 facing each other areprovided two controls 7, 8, which on the edges facing each other areformed as rack bars with teeth 9, 10.

On the inside the frame 1 is provided with a curtain consisting of atleast one layer 14 of windproof and elastic material of such dimensionthat the inside may be covered.

This layer 14 is secured to the side of an edging 13 provided on theedge of the layer 14, which is secured as well to the sides of a numberof lamellas or slats 11 having preferably a rectangular section andhaving their larger sides directed in transverse direction in relationto the plane of the frame 1.

The slats 11 and the edging 13 are distributed at equal distances overthe layer 14 and extend parallel with the long sides 2, 3 of the frame1.

Preferably there is provided a layer 14 on each side of the slats 11 andthe edging 13.

The slats 11 are provided with recesses 12, which are formed to engageslidably with the controls 7, 8 to the effect that the slats 11 may becaused to move vertically within the plane of the frame.

The edging 13 has recesses 12 as well corresponding to the recesses atthe ends, however the edging 13 is formed differently as compared to theslats 11 as will be described in detail below.

The elastic layer 14 may for example be a woven fabric or a man-madematerial, only it must be pliable, when the distance between the slats11 and the edging 13 decreases, or the slats are folded together face toface.

The slats 11 and the edging 13 may also be provided with one or moreperforations 15 evenly distributed over the lengths of the slats so thatthe frame if made with a considerable length, may be fitted withadditional controls for the slats 11 and the edging 13 within the planeof the frame and to absorb possible wind pressure against the layer 14.

Like the controls 7, 8 these additional controls may be formed withteeth 9, 10. If so, the perforations 15 will be of rectangular shape. Ifthe guides are without teeth, they will normally have a circularsection, and so the perforations 15 will be circular as shown in FIG. 2.

The lower slat 11 is secured to one of the long sides 3 of the frame 1,for example by means of screws in perforations 15, which may not beutilized, or other appropriate openings, and it will be understood thata movement upwards of the edging 13 wil cause the layer or the layers 14to expand or stretch out so that the inside of the frame is covered, andthat a movement of the edging 13 downwards will cause the layer or thelayers 14 to fold, resulting in the maximum opening 32 possible betweenthe edging 13 and the upper long side 2 of the frame 1, the inside ofthe opening 32 being defined alone by the possibility of foldingtogether the slats 11 and the edging 13. The slats remain secured to theplane of the frame 1 by the interaction between the controls 7, 8 andthe recesses 12 at the ends of the slats 11 and the mentioned recessesof the edging 13.

The edging 13 has a longitudinal channel 16 to receive the second rackbar 17 which is slidable in the longitudinal direction of the channel16.

The rack bar 17 is provided with teeth extending over a limited lengthat the ends of its edge or surface facing downwards.

The recesses extend further from the ends of the edging 13 than therecesses 12 of the slats 11. The recesses thus are adapted to receive apinion consisting of a first 19 and a second gear 20 of different sizes,mounted surface to surface and in mutual locked position on a shaft 28,which can be received rotatably in a bore 22 extending through therecess and at right angles to the plane of the frame 1.

The bore 22 is placed in the edging 13 such that the first gear 19having the larger diameter of the two gears 19, 20, can interact withthe teeth 9, 10 of the controls 7, 8, and the second gear 20 caninteract with the teeth 21 at the ends of the second rack bar 17.

A movement by the second rack bar 17 in the channel 16 therefore, willcause the gear 20 and consequently the first gear 19 as well to rotateas a result of the interaction between the teeth 21 and the second gear20.

Since the first gear 19 is in mesh with the teeth 9, 10 of the controls7, 8, this rotation of the first gear 19 will cause the end in questionof the edging 13 to move upwards or downwards depending upon thedirection of movement of the second rack bar 17.

When the teeth 9, 10 are mounted on the edges of the controls 7, 8facing each other as shown in FIG. 1, it is necessary to expand therecess at one end of the edging 13 to such an extent that a reversinggear, which is not illustrated, can be inserted between the teeth 21 andthe second gear in order to reverse the direction of rotation of thepinion, which is provided at this end of the edging 13, for paralleldisplacement of the edging 13 in the frame 1.

If such intermediate reversing gear is undesirable, the controls 7, 8should be mounted so that both teeth 9, 10 face the same end of theframe 1.

When selecting the size of the teeth 9, 10 and 21 as well as thediameters and sizes of the teeth of the gears 19, 20 an adaptation maybe made to the vertical displacement of the edging 13 from a givenhorizontal displacement of the rack bar 17.

Furthermore, it may be convenient to mount the controls provided withteeth at a distance from the two short sides 4, 5 of the frame, to theeffect that a larger longitudinal displacement of the second rack bar 17can be achieved, without risking its ends running against the shortsides 4, 5 of the frame. At the same time the possibility of adaptingthe sizes of the teeth 9, 10 and the gears 19 and 20 will improve whenplacing the controls this way. If controls with teeth 9, 10 are mountedat a distance from the short sides 4, 5, the edging 13 opposite eachcontrol must be provided with a set of gears 19, 20, and the tooth rack17 must have teeth to interact herewith

Furthermore, the edging 13 has a longitudinal perforation 23 between thechannel 16 and the side of the edging which is adapted to face theinterior of the building when the frame 1 has been installed. Thisperforation 23 is of a length corresponding to the maximum movementpossible of the second rack bar 17, and a corresponding perforation hasbeen provided in the layer 14.

The numerous channels and recesses of the edging 13 can advantageouslybe effected by having the edging 13 consist of several layers of slats.

On the above mentioned side of the edging 13 and the layer 14 ahydraulic cylinder 24 has been provided, which is secured appropriatelyto the edging 13, for example by means of a screw 25 at the closed endof the cylinder. The hydraulic cylinder 24 is covered by a screen 33.

The cylinder 24 has an inside piston 32 and a piston rod 26 connectedhereto extending out of the cylinder and is connected to the rack bar 17with its free end, whereby the connection may have been provided by astud extending from the piston rod through the perforation 23 into therack bar 17.

The hydraulic cylinder 24 is filled with a fluid having a rather highthermal expansion coefficient to the effect that the volume of the fluidmay vary as much as possible concurrently with the variations of thefluid temperature.

The inside piston 32 mentioned is a so-called diving piston, which is tosay that its cross section is considerably smaller that of the hydrauliccylinder 24.

As a result, even an insignificant change of the fluid volume will causea comparatively big longitudinal movement of the inside piston of thecylinder.

The piston rod 26 is sealed in a conventional manner in relation to thecylinder 24 by means of sealing devices, which are not illustrated inthe drawing.

The outside of the frame 1 is fitted with a grid 29 having horizontalopenings 30 for admittance of the outside air into and through theframe 1. In order to prevent precipitation and solar rays from reachinginto the frame the grid 29 is provided with louvres 31 extending fromthe upper edge of each of the openings 30, and sloping downwards andoutwards, and in addition the frame 1 may be provided with a fine-meshednet on either side, which is not illustrated in the drawing, in order tokeep out insects.

The sheet member according to the invention works in the following way:

When rays of sunlight enter through the transparent material forming thewalls and roof of the building, the temperature inside the building willincrease.

As a result of this increase of temperature the fluid contained in thehydraulic cylinder 24 and the inside piston will warm up and expand tothe effect that the piston rod 26 is pushed in a direction out of thecylinder. Through the stud 27 which moves freely in the longitudinalperforation 23 of the edging 13 and the layer 14, the second rack bar 17will be included as well in the same direction in relation to the edging13 and the teeth 21, as a result of their engagement with the secondgear 20, and the intermediate reversing gears, if any, will cause thetwo first gears 19 to rotate to the effect that the edging 13 is moveddownwards while still remaining parallel to the long sides 2, 3 of theframe 1.

The curtain is folded together leaving an opening 32 between the upperlong side 2 of the frame 1 and the edging 13.

At the same time, and possibly even a little earlier, temperaturedetecting means have caused the second opening provided higher in thebuilding to open to the effect that some of the heated air can escape.An air current is now created through the opening 32 of the frame 1, asa result of which the temperature will gradually assume a degree whichis determined in part by the ventilation and in part by the intensity ofthe sunlight and a temperature of the fluid in the cylinder 24corresponding hereto.

The above described movements of the device is a comparatively slowprocess, and the device will find an opening 32 of reasonable size whichwill ensure maintenance of a predetermined temperature inside thebuilding.

When solar radiation ceases resulting in the temperature inside thebuilding dropping below the predetermined level, the device will againclose the opening 32.

What is claimed is:
 1. A member for venting buildings, in particularwinter gardens, sun lounges or greenhouses, comprising a rectangularframe (1) and at least one layer (14) of windproof material said atleast one layer is movable by means of a temperature detectingactivation mechanism (24, 26) between a closed position, wherein theopening of the frame (1) is filled up by the layer (14), and an openposition, wherein there is a space between one side (2) of the frame (1)and a first edge of the layer (14), the opposite second edge of which isclosely connected to the frame (1), said activation mechanism (24, 26)being mounted on the side of the frame (1) which is adapted to face theinterior of the building, characterized in that the frame (1) has atleast two controls (7, 9) extending parallel to the first two sides (4,5) of the frame and are connected to its two other sides (2, 3), thatthe layer (14) is elastic and has one side secured to several lamellasor slats (11, 13), which are mounted at equal distance and parallel tothe two other sides (2, 3) of the frame, said lamellas or slats havingperforations (12, 13) to slidably receive the controls (7, 8) that eachcontrol (7, 8) is formed as a first rack bar (9, 10), which is in meshwith a first gear (19) being secured locked against movement to a secondgear (20), and that the first (19) and the second gear (20) are mountedrotatably on a shaft (28) provided in one of the slats (13), the secondgear (20) being in mesh with a second rack bar (17) extending in achannel (16) in the slat (13) carrying the shaft and is adapted to bemoved by the activation mechanism (24, 26) in its longitudinaldirection.
 2. Member according to claim 1, characterized in that thefirst gear (19) has a larger diameter than that of the second gear (20).3. Member according to claims 1 or 2, characterized in that thetemperature detecting activation mechanism (24, 26) is a hydrauliccylinder (24), which is secured to the slat (13) carrying the shaft andhas a piston with a cross section smaller than that of the cylinder(24), and that the piston has a piston rod (26), which is connected tothe second rack bar (17).
 4. Member according to claim 3, characterizedin that the hydraulic cylinder (24) is covered by a screen.